I think the "executive producer" thing is more of an honorary title.
Yamauchi was brilliant, yes. He understood talent, understood the winds of the industry and how to make Nintendo a powerful corporate entity. So much of what made Nintendo Nintendo is a result of his actions.
However, unlike Iwata, Yamuchi wasn't a game designer or a programmer. He found the talent to make great games and brought it forward- he didn't get involved in the games themselves. Because of his influence, names like Yokoi and Miyamoto are ones we know today.
Iwata started out in the trenches, as it were, so his experiences were vastly different from his predecessor. Because of his heavy, direct involvement in development, I think yes, there will continue to be games all the way up until 2018 that bear his name in some way.